12. Register Descriptions
363
PowerSpan II User Manual
80A1010_MA001_09
Integrated Device Technology
www.idt.com
12.5.67
I2O Inbound Free List Top Pointer Register
TOP:
This pointer gives the address offset for the Inbound Free List Top Pointer from PB_I2O_BS.
This pointer is initialized by the IOP and can be incremented by four by writing a 1 to the INCR bit in
the
“Inbound Free List Top Pointer Increment Register” on page 364
Register Name: IFL_TOP
Register Offset: 0x514
PCI
Bits
Function
PB
Bits
31-24
PB_I2O_BS
0-7
23-16
PB_I2O_BS
TOP
8-15
15-08
TOP
16-23
07-00
TOP
0
0
24-31
Name
Type
Reset
By
Reset
State
Function
PB_I2O_BS
[11:0]
R
PRI_RST
0
Processor Bus I2O Base Address
TOP [17:0]
R/W
PRI_RST
0
Inbound Free List Top Pointer
This pointer gives the address offset for the Inbound
Free List Top Pointer from PB_I2O_BS.
If the initial values of the Inbound Free List Bottom and Top pointers are the
same, the inbound free list is empty. The user can program the Top pointer to be
four less than the Bottom pointer and then set the INCR bit in the
List Top Pointer Increment Register” on page 364
register to make the inbound
free list full.